Topiramate intervention to prevent transformation of episodic migraine: the topiramate INTREPID study

Nonspecific oral medications versus anti-calcitonin gene-related peptide monoclonal antibodies for migraine: A systematic review and meta-analysis of randomized controlled trials

OBJECTIVE

To compare calcitonin gene-related peptide monoclonal antibodies (CGRP mAbs) versus nonspecific oral migraine preventives (NOEPs).

BACKGROUND

Insurers mandate step therapy with NOEPs before approving CGRP mAbs.

METHODS

Databases were searched for class I or II randomized controlled trials (RCTs) comparing CGRP mAbs or NOEPs versus placebo for migraine prevention in adults. The primary outcome measure was monthly migraine days (MMD) or moderate to severe headache days.

RESULTS

Twelve RCTs for CGRP mAbs, 5 RCTs for topiramate, and 3 RCTs for divalproex were included in the meta-analysis. There was high certainty that CGRP mAbs are more effective than placebo, with weighted mean difference (WMD; 95% confidence interval) of -1.64 (-1.99 to -1.28) MMD, which is compatible with small effect size (Cohen's d -0.25 [-0.34 to -0.16]). Certainty of evidence that topiramate or divalproex is more effective than placebo was very low and low, respectively (WMD -1.45 [-1.52 to -1.38] and -1.65 [-2.30 to -1.00], respectively; Cohen's d -1.25 [-2.47 to -0.03] and -0.48 [-0.67 to -0.29], respectively). Trial sequential analysis showed that information size was adequate and that CGRP mAbs had clear benefit versus placebo. Network meta-analysis showed no statistically significant difference between CGRP mAbs and topiramate (WMD -0.19 [-0.56 to 0.17]) or divalproex (0.01 [-0.73 to 0.75]). No significant difference was seen between topiramate or divalproex (0.21 [-0.45 to 0.86]).

CONCLUSIONS

There is high certainty that CGRP mAbs are more effective than placebo, but the effect size is small. When feasible, CGRP mAbs may be prescribed as first-line preventives; topiramate or divalproex could be as effective but are less well tolerated. The findings of this study support the recently published 2024 position of the American Headache Society on the use of CGRP mAbs as the first-line treatment.

Differences in Neuropathology between Nitroglycerin-Induced Mouse Models of Episodic and Chronic Migraine

Multiple animal models of migraine have been used to develop new therapies. Understanding the transition from episodic (EM) to chronic migraine (CM) is crucial. We established models mimicking EM and CM pain and assessed neuropathological differences. EM and CM models were induced with single NTG or multiple injections over 9 days. Mechanical hypersensitivity was assessed. Immunofluorescence utilized c-Fos, NeuN, and Iba1. Proinflammatory and anti-inflammatory markers were analyzed. Neuropeptides (CGRP, VIP, PACAP, and substance P) were assessed. Mechanical thresholds were similar. Notable neuropathological distinctions were observed in Sp5C and ACC. ACC showed increased c-Fos and NeuN expression in CM (p < 0.001) and unchanged in EM. Sp5C had higher c-Fos and NeuN expression in EM (p < 0.001). Iba1 was upregulated in Sp5C of EM and ACC of CM (p < 0.001). Proinflammatory markers were strongly expressed in Sp5C of EM and ACC of CM. CGRP expression was elevated in both regions and was higher in CM. VIP exhibited higher levels in the Sp5C of EM and ACC of CM, whereas PACAP and substance P were expressed in the Sp5C in both models. Despite similar thresholds, distinctive neuropathological differences in Sp5C and ACC between EM and CM models suggest a role in the EM to CM transformation.

High Dosage Omega-3 Fatty Acids Outperform Existing Pharmacological Options for Migraine Prophylaxis: A Network Meta-Analysis

Migraine is a highly prevalent neurologic disorder with prevalence rates ranging from 9% to 18% worldwide. Current pharmacologic prophylactic strategies for migraine have limited efficacy and acceptability, with relatively low response rates of 40% to 50% and limited safety profiles. Eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) are considered promising therapeutic agents for migraine prophylaxis. The aim of this network meta-analysis (NMA) was to compare the efficacy and acceptability of various dosages of EPA/DHA and other current Food and Drug Administration-approved or guideline-recommended prophylactic pharmacologic interventions for migraine. Randomized controlled trials (RCTs) were eligible for inclusion if they enrolled participants with a diagnosis of either episodic or chronic migraine. All NMA procedures were conducted under the frequentist model. The primary outcomes assessed were 1) changes in migraine frequency and 2) acceptability (i.e., dropout for any reason). Secondary outcomes included response rates, changes in migraine severity, changes in the frequency of using rescue medications, and frequency of any adverse events. Forty RCTs were included (N = 6616; mean age = 35.0 y; 78.9% women). Our analysis showed that supplementation with high dosage EPA/DHA yields the highest decrease in migraine frequency [standardized mean difference (SMD): -1.36; 95% confidence interval (CI): -2.32, -0.39 compared with placebo] and the largest decrease in migraine severity (SMD: -2.23; 95% CI: -3.17, -1.30 compared with placebo) in all studied interventions. Furthermore, supplementation with high dosage EPA/DHA showed the most favorable acceptability rates (odds ratio: 1.00; 95% CI: 0.06, 17.41 compared with placebo) of all examined prophylactic treatments. This study provides compelling evidence that high dosage EPA/DHA supplementation can be considered a first-choice treatment of migraine prophylaxis because this treatment displayed the highest efficacy and highest acceptability of all studied treatments. This study was registered in PROSPERO as CRD42022319577.

The history and rationale of the development of new drugs for migraine treatment

Migraine is one of the most prevalent and disabling diseases in the world. Migraine attack treatments and prophylactic treatments of this disease are essential to lessen its individual, social, and economic impact. This is a narrative review of the main drugs used for treating migraine, as well as the experimental models and the theoretical frameworks that led to their development. Ergot derivatives, triptans, non-steroid anti-inflammatory drugs, tricyclic antidepressants, beta-blockers,: flunarizine,: valproic acid,: topiramate, onabotulinumtoxin A, ditans, monoclonal antibodies against CGRP and its receptor, and gepants are discussed. Possible therapeutic targets for the development of new drugs that are under development are also addressed. Many of the drugs currently in use for treating migraine were developed for the treatment of other diseases, but have proven effective for the treatment of migraine, expanding knowledge about the disease. With a better understanding of the pathophysiology of migraine, new drugs have been and continue to be developed specifically for the treatment of this disease.

Risk factors for migraine disease progression: a narrative review for a patient-centered approach

BACKGROUND

In individuals with migraine, attacks may increase in frequency, severity, or both. Preventing migraine progression has emerged as a treatment goal in headache subspecialty practice, but there may be less awareness in general neurology or primary care settings where most people with migraine who seek treatment consult. Herein, we review the definition of and risk factors for migraine progression and consider strategies that could reduce its risk.

METHODS

A group of headache expert healthcare professionals, clinicians, and researchers reviewed published evidence documenting factors associated with increased or decreased rates of migraine progression and established expert opinions for disease management recommendations. Strength of evidence was rated as good, moderate, or based solely on expert opinion, using modified criteria for causation developed by AB Hill.

RESULTS

Migraine progression is commonly operationally defined as the transition from ≤ 15 to ≥ 15 monthly headache days among people with migraine; however, this does not necessarily constitute a fundamental change in migraine biology and other definitions should be considered. Established and theoretical key risk factors for migraine progression were categorized into five domains: migraine disease characteristics, treatment-related factors, comorbidities, lifestyle/exogenous factors, and demographic factors. Within these domains, good evidence supports the following risk factors: poorly optimized acute headache treatment, cutaneous allodynia, acute medication overuse, selected psychiatric symptoms, extra-cephalic chronic pain conditions, metabolism-related comorbidities, sleep disturbances, respiratory conditions, former/current high caffeine intake, physical inactivity, financial constraints, tobacco use, and personal triggers as risk factors. Protective actions that may mitigate migraine progression are sparsely investigated in published literature; our discussion of these factors is primarily based on expert opinion.

CONCLUSIONS

Recognizing risk factors for migraine progression will allow healthcare providers to suggest protective actions against migraine progression (Supplementary Fig. 1). Intervention studies are needed to weight the risk factors and test the clinical benefit of hypothesized mitigation strategies that emerge from epidemiological evidence.

European Headache Federation (EHF) critical reappraisal and meta-analysis of oral drugs in migraine prevention - part 3: topiramate

OBJECTIVE

Topiramate is a repurposed first-line treatment for migraine prophylaxis. The aim of this systematic review and meta-analysis is to critically re-appraise the existing evidence supporting the efficacy and tolerability of topiramate.

METHODS

A systematic search in MEDLINE, EMBASE, Cochrane CENTRAL, and ClinicalTrials.gov was performed for trials of pharmacological treatment in migraine prophylaxis as of August 13, 2022, following the Preferred Reporting Items for Systematic Reviews (PRISMA). Randomized controlled trials in adult patients that used topiramate for the prophylactic treatment of migraine, with placebo as active comparator, were included. Two reviewers independently screened the retrieved studies and extracted all data. Outcomes of interest were the 50% responder rates, the reduction in monthly migraine days, and adverse events leading to treatment discontinuation. Results were pooled and meta-analyzed, with sensitivity analysis based on the risk of bias of the studies, the monthly migraine days at baseline, and the previous use of other prophylactic treatments. Certainty evidence was judged according to the GRADE framework.

RESULTS

Eight out of 10,826 studies fulfilled the inclusion/exclusion criteria, accounting for 2,610 randomized patients. Six studies included patients with episodic migraine and two with chronic migraine. Topiramate dose ranged from 50 to 200 mg/day, and all studies included a placebo arm. There was a high certainty that topiramate: 1) increased the proportion of patients who achieved a 50% responder rate in monthly migraine days, compared to placebo [relative risk: 1.61 (95% confidence interval (CI): 1.29-2.01); absolute risk difference: 168 more per 1,000 (95% CI: 80 to 278 more)]; 2) was associated with 0.99 (95% CI: 1.41-0.58) fewer migraine days than placebo; 3) and had a higher proportion of patients with adverse events leading to treatment discontinuation [absolute risk difference 80 patients more per 1,000 (95% CI: 20 to 140 more patients)].

CONCLUSIONS

There is high-quality evidence of the efficacy of topiramate in the prophylaxis of migraine, albeit its use poses a risk of adverse events that may lead to treatment discontinuation, with a negative effect on patient satisfaction and adherence to care.

Breaking the cycle: unraveling the diagnostic, pathophysiological and treatment challenges of refractory migraine

Background

Refractory migraine is a poorly described complication of migraine in which migraine has chronified and become resistant to standard treatments. The true prevalence is unknown, but medication resistance is common in headache clinic patient populations. Given the lack of response to treatment, this patient population is extremely difficult to treat with limited guidance in the literature.

Objective

To review the diagnostic, pathophysiological, and management challenges in the refractory migraine population.

Discussion

There are no accepted, or even ICHD-3 appendix, diagnostic criteria for refractory migraine though several proposed criteria exist. Current proposed criteria often have low bars for refractoriness while also not meeting the needs of pediatrics, lower socioeconomic status, and developing nations. Pathophysiology is unknown but can be hypothesized as a persistent "on" state as a progression from chronic migraine with increasing central sensitization, but there may be heterogeneity in the underlying pathophysiology. No guidelines exist for treatment of refractory migraine; once all guideline-based treatments are tried, treatment consists of n-of-1 treatment trials paired with non-pharmacologic management.

Conclusion

Refractory migraine is poorly described diagnostically, its pathophysiology can only be guessed at by extension of chronic migraine, and treatment is more the art than science of medicine. Navigating care of this refractory population will require multidisciplinary care models and an emphasis on future research to answer these unknowns.

The comparative effectiveness of migraine preventive drugs: a systematic review and network meta-analysis

OBJECTIVE

While there are several trials that support the efficacy of various drugs for migraine prophylaxis against placebo, there is limited evidence addressing the comparative safety and efficacy of these drugs. We conducted a systematic review and network meta-analysis to facilitate comparison between drugs for migraine prophylaxis.

METHODS

We searched MEDLINE, EMBASE, CENTRAL, and clinicaltrials.gov from inception to August 13, 2022, for randomized trials of pharmacological treatments for migraine prophylaxis in adults. Reviewers worked independently and in duplicate to screen references, extract data, and assess risk of bias. We performed a frequentist random-effects network meta-analysis and rated the certainty (quality) of evidence as either high, moderate, low, or very low using the GRADE approach.

RESULTS

We identified 74 eligible trials, reporting on 32,990 patients. We found high certainty evidence that monoclonal antibodies acting on the calcitonin gene related peptide or its receptor (CGRP(r)mAbs), gepants, and topiramate increase the proportion of patients who experience a 50% or more reduction in monthly migraine days, compared to placebo. We found moderate certainty evidence that beta-blockers, valproate, and amitriptyline increase the proportion of patients who experience a 50% or more reduction in monthly migraine days, and low certainty evidence that gabapentin may not be different from placebo. We found high certainty evidence that, compared to placebo, valproate and amitriptyline lead to substantial adverse events leading to discontinuation, moderate certainty evidence that topiramate, beta-blockers, and gabapentin increase adverse events leading to discontinuation, and moderate to high certainty evidence that (CGRP(r)mAbs) and gepants do not increase adverse events.

CONCLUSIONS

(CGRP(r)mAbs) have the best safety and efficacy profile of all drugs for migraine prophylaxis, followed closely by gepants.

The temporal trend of placebo response in migraine prevention from 1990 to 2021: a systematic literature review and meta-analysis with regression

BACKGROUND

Migraine affects 1.1 billion people globally and is the second leading cause of disability worldwide. In clinical trials, treatment efficacy is evaluated by comparing the differential responses in the treatment and placebo arms. Although placebo response in preventive migraine trials has been studied, there is limited research examining temporal trends. This study evaluates the trend of placebo response over thirty years in migraine prevention trials and investigates the association of potential confounders, such as patient, treatment, and study characteristics on placebo response using meta-analysis with regression.

METHODS

We conducted literature searches from January 1990 to August 2021 in bibliographical databases (PubMed, Cochrane Library, and EMBASE). Studies were selected according to PICOS criteria and included randomized, double-blind, placebo-controlled trials evaluating preventive migraine treatments in adult patients diagnosed with episodic or chronic migraine, with or without aura. The protocol was registered with PROSPERO (CRD42021271732). Migraine efficacy outcomes included were either continuous (e.g., monthly migraine days) or dichotomous (e.g., ≥ 50% responder rate (yes/no)). We assessed the correlation of the change in outcome from baseline in the placebo arm, with the year of publication. The relationship between placebo response and year of publication was also assessed after accounting to confounders.

RESULTS

A total of 907 studies were identified, and 83 were found eligible. For the continuous outcomes, the change from baseline in mean placebo response showed an increase over the years (rho = 0.32, p = 0.006). The multivariable regression analysis also showed an overall increase in placebo response over the years. The correlation analysis of dichotomous responses showed no significant linear trend between publication year and mean placebo response (rho = 0.08, p = 0.596). Placebo response also varied by route of administration.

CONCLUSION

Placebo response increased over the past 30 years in migraine preventive trials. This phenomenon should be considered when designing clinical trials and conducting meta-analyses.

CGRP monoclonal antibodies in migraine: an efficacy and tolerability comparison with standard prophylactic drugs

BACKGROUND

Several drugs are available for the preventive treatment of both episodic and chronic migraine. The choice of which therapy to initiate first, second, or third is not straightforward and is based on multiple factors, including general efficacy, tolerability, potential for serious adverse events, comorbid conditions, and costs. Recently, a new class of migraine preventive drugs was introduced, i.e. monoclonal antibodies against calcitonin gene-related peptide (CGRP) or its receptor.

METHODS

The present article summarizes the evidence gathered with this new migraine preventive drug class from randomized placebo-controlled clinical trials. It further puts this into perspective next to the evidence gained by the most widely used agents for the prevention of episodic and chronic migraine with an emphasis on efficacy and the robustness with which this efficacy signal was obtained.

RESULTS

Although being a relatively new class of migraine preventive drugs, monoclonal antibodies blocking the CGRP pathway have an efficacy which is at least comparable if not higher than those of the currently used preventive drugs. Moreover, the robustness of this efficacy signal is substantiated by several randomized clinical trials each including large numbers of patients. In addition, because of their excellent tolerability and with long-term safety data emerging, they seem to have an unprecedented efficacy over adverse effect profile, clearly resulting in an added value for migraine prevention.

CONCLUSIONS

Balancing the data presented in the current manuscript with additional data concerning long term safety on the one hand and cost issues on the other hand, can be of particular use to health policy makers to implement this new drug class in the prevention of migraine.

An underrepresented majority: A systematic review utilizing allodynic criteria to examine the present scarcity of discrete animal models for episodic migraine

BACKGROUND

Despite increasing evidence differentiating episodic and chronic migraine, little work has determined how currently utilized animal models of migraine best represent each distinct disease state.

AIM

In this review, we seek to characterize accepted preclinical models of migraine-like headache by their ability to recapitulate the clinical allodynic features of either episodic or chronic migraine.

METHODS

From a search of the Pu bMed database for "animal models of migraine", "headache models" and "preclinical migraine", we identified approximately 80 recent (within the past 20 years) publications that utilized one of 10 different models for migraine research. Models reviewed fit into one of the following categories: Dural KCl application, direct electrical stimulation, nitroglycerin administration, inflammatory soup injection, CGRP injection, medication overuse, monogenic animals, post-traumatic headache, specific channel activation, and hormone manipulation. Recapitulation of clinical features including cephalic and extracephalic hypersensitivity were evaluated for each and compared.

DISCUSSION

Episodic migraineurs comprise over half of the migraine population, yet the vast majority of current animal models of migraine appear to best represent chronic migraine states. While some of these models can be modified to reflect episodic migraine, there remains a need for non-invasive, validated models of episodic migraine to enhance the clinical translation of migraine research.

Anti-CGRP monoclonal antibodies for migraine prevention: A systematic review and likelihood to help or harm analysis

INTRODUCTION AND OBJECTIVE

Monoclonal antibodies targeting the calcitonin gene-related peptide pathway (anti-CGRP mAbs) have shown promising efficacy in randomised clinical trials for the prevention of episodic and chronic migraine, but no head-to-head comparisons with established treatments are available. We aimed to examine absolute differences in benefit-risk ratios between anti-CGRP mAbs, topiramate and propranolol for the prevention of episodic migraine and between anti-CGRP mAbs, topiramate and onabotulinumtoxinA for the prevention of chronic migraine using a likelihood to help versus harm analysis.

METHODS

The number of patients needed to be treated for a patient to achieve ≥ 50% reduction in migraine days (NNTB_50%) was used as an effect size metric of efficacy. The number of patients needed to be treated for a patient to experience an adverse event that led to treatment discontinuation (NNTH_D-AE) was used as a measure of risk. Likelihood to help versus harm values - which are the ratios of NNTH:NNTB - were calculated using data from phase 3 randomised clinical trials.

RESULTS

All agents tested were more likely to be beneficial than harmful (likelihood to help versus harm > 1) with the exception of topiramate at 200 mg per day for the prevention of episodic migraine. Anti-CGRP mAbs in all tested doses had higher LHH values than propranolol or topiramate for episodic migraine and onabotulinumtoxinA or topiramate for chronic migraine prevention. Fremanezumab had the highest LHH ratio in episodic migraine and galcanezumab in chronic migraine.

CONCLUSION

This analysis showed that anti-CGRP mAbs exhibit a more favourable benefit-risk ratio than established treatments for episodic and chronic migraine. Head-to-head studies are needed to confirm these results.

Indirect Comparison of Topiramate and Monoclonal Antibodies Against CGRP or Its Receptor for the Prophylaxis of Episodic Migraine: A Systematic Review with Meta-Analysis

BACKGROUND

Head-to-head comparator trials between first-line oral migraine preventatives and the new monoclonal antibodies (mAbs) blocking the calcitonin gene-related peptide (CGRP) pathway have not been published to date.

OBJECTIVES

This study aimed to indirectly compare the clinical efficacy and safety of mAbs against CGRP or its receptor (CGRPR) and topiramate in episodic migraine prophylaxis using meta-analysis.

METHODS

We included controlled trials testing efficacy and safety of erenumab, galcanezumab, fremanezumab, eptinezumab, and topiramate in adults diagnosed with episodic migraine. We searched PubMed, Cochrane Central Register of Controlled Trials (CENTRAL), and ClinicalTrials.gov from January 2000 to November 2020. We used the Risk of Bias 2 (RoB2) tool to assess the risk of bias and report pooled mean effects (mean difference and risk ratio) as estimated in a random effect model. For efficacy analysis, we determined the reduction of monthly migraine days (MMDs), reduction of days with acute medication (AMDs), and 50% responder rates (50% RR). For safety, we determined adverse events (AEs) occurring in ≥ 2% of study participants and the number of patients who discontinue treatment due to AEs (DAEs). The number needed to treat (NNT) and to harm (NNH) were estimated as well as the likelihood to help or harm (LLH).

RESULTS

We included 13 trials involving 7557 patients: three trials with erenumab, two trials with galcanezumab, two trials with fremanezumab, one trial with eptinezumab, and five trials with topiramate, for the prophylaxis of episodic migraine in adults. The placebo-subtracted reduction (pooled mean difference) of MMDs were - 1.55 (95% CI - 1.86 to - 1.24; active drug n = 3326 vs placebo n = 2219, 8 studies) for the CGRP(R) mAb and - 1.11 (95% CI - 1.62 to - 0.59; active drug n = 1032 vs placebo n = 543, 4 studies) for topiramate (p for subgroup difference = 0.15). 'Cognitive' and 'sensory & pain'-related adverse events occurred more often in patients treated with topiramate compared with those treated with a CGRP(R) mAb (p for subgroup difference 0.03 and < 0.001, respectively). Based on the 50% RR and DAE, the NNT, NNH, and LHH for the CGRP(R) mAbs were 6, 130, and 24.3:1, respectively. For topiramate, these values were 7, 9, and 1.8:1, respectively.

CONCLUSION

The efficacy of CGRP(R) mAbs to reduce migraine days does not differ from topiramate. However, the safety profile is in favor of the CGRP(R) mAbs, with a higher likelihood to help than to harm compared with topiramate. The diversity of endpoint determination and the heterogeneity between studies for some endpoints cause some limitations for this study.

The association between melatonin and episodic migraine: A pilot network meta-analysis of randomized controlled trials to compare the prophylactic effects with exogenous melatonin supplementation and pharmacotherapy

Although exogenous melatonin supplementation has been suggested to be effective for episodic migraine prophylaxis, there is no conclusive evidence comparing the efficacy of exogenous melatonin supplementation to the other FDA-approved pharmacotherapy for episodic migraine prophylaxis. The aim of the current network meta-analysis (NMA) was to compare the efficacy of exogenous melatonin supplementation in patients with episodic migraine. The randomized placebo-controlled trials or randomized controlled trials (RCTs) incorporating a placebo in the study designs were included in our analyses. All of the NMA procedures were conducted under the frequentist model. The primary outcome was changes in frequency of migraine days and response rate after migraine prophylaxis with melatonin supplementation or pharmacological interventions. We included 25 RCTs in total with 4499 patients (mean age = 36.0 years, mean female proportion = 78.9%). The NMA demonstrated that migraine prophylaxis with oral melatonin 3 mg/d (immediate-release) at bedtime was associated with the greatest improvement in migraine frequency [mean difference = -1.71 days, 95% confidence interval (CI): -3.27 to -0.14 days compared to placebo] and the second highest response rate (odds ratio = 4.19, 95% CI = 1.46 to 12.00 compared to placebo). Furthermore, oral melatonin 3 mg (immediate-release) at bedtime was the most preferred pharmacological intervention among all of the investigated interventions when improvements in migraine frequency, response rate, dropout rate, and rates of any adverse events were taken into account. This pilot NMA suggests the potential prophylactic role of exogenous melatonin supplementation in patients with episodic migraine.

Placebo and nocebo phenomena in anti- CGRP monoclonal antibody trials for migraine prevention: a meta-analysis

High placebo and low nocebo phenomena mirror high positive expectations for a novel treatment, among other reasons. In a meta-analysis aimed to identify placebo and nocebo phenomena in the placebo-controlled randomized trials (RCTs) with the monoclonal antibodies targeting the calcitonin gene-related peptide pathway (anti-CGRP mAbs) all the placebo-treated patients were pooled and compared with the placebo-treated patients in RCTs with topiramate and onabotulinum toxin A (OBTA). In episodic migraine (EM), the proportion of placebo-treated patients who achieved the 50% responder rate (placebo) was 32.7% (95% CI 28.6%-37.0%) in anti-CGRP mAbs vs. 24.4% (95% CI 20.5%-28.5%) in topiramate trials. The proportion of dropouts due to adverse events in placebo-treated patients (nocebo) was 1.9% (95% CI 1.4%-2.6%) in anti-CGRP mAbs vs. 9.9% (95% CI 7.7%-12.3%) in topiramate RCTs. In chronic migraine (CM), the placebo 50% responder rate was 23.6% (95% CI 11.2%-38.8%) in anti-CGRP mAbs RCTs vs. 36.4% (95% CI 32.6%-39.3%) in RCTs with OBTA. The nocebo dropout in anti-CGRP mAbs and OBTA RCTs was 1.4% (95% CI 0.8%-2.1%) and 0.9 (95% CI 0.3%-1.7%), respectively. The stronger placebo and weaker nocebo phenomena in RCTs with anti-CGRP mAbs vs. those with topiramate in the prophylaxis of EM, may decisively determine anti-CGRP mAbs treatment success. No differences were detected between the anti-CGRP mAbs and OBTA in the treatment of CM.

Consensus of the Hellenic Headache Society on the diagnosis and treatment of migraine

More than 0.6 million people suffer from disabling migraines in Greece causing a dramatic work loss, but only a small proportion of migraineurs attend headache centres, most of them being treated by non-experts. On behalf of the Hellenic Headache Society, we report here a consensus on the diagnosis and treatment of adult migraine that is based on the recent guidelines of the European Headache Federation, on the principles of Good Clinical Practice and on the Greek regulatory affairs. The purposes are three-fold: (1) to increase awareness for migraine in Greece; (2) to support Greek practitioners who are treating migraineurs; and (3) to help Greek migraineurs to get the most appropriate treatment. For mild migraine, symptomatic treatment with high dose simple analgesics is suggested, while for moderate to severe migraines triptans or non-steroidal anti-inflammatory drugs, or both, should be administered following an individually tailored therapeutic strategy. A rescue acute treatment option should always be advised. For episodic migraine prevention, metoprolol (50–200 mg/d), propranolol (40–240 mg/d), flunarizine (5–10 mg/d), valproate (500–1800 mg/d), topiramate (25–100 mg/d) and candesartan (16–32 mg/d) are the drugs of first choice. For chronic migraine prevention topiramate (100-200 mg/d), valproate (500–1800 mg/d), flunarizine (5–10 mg/d) and venlafaxine (150 mg/d) may be used, but the evidence is very limited. Botulinum toxin type A and monoclonal antibodies targeting the CGRP pathway (anti-CGRP mAbs) are recommended for patients suffering from chronic migraine (with or without medication overuse) who failed or did not tolerate two previous treatments. Anti-CGRP mAbs are also suggested for patients suffering from high frequency episodic migraine (≥8 migraine days per month and less than 14) who failed or did not tolerate two previous treatments.

Episodic primary migraine headache: supplementary prophylaxis with Pycnogenol® prevents attacks and controls oxidative stress

BACKGROUND

This registry study investigated the supplement Pycnogenol® on migraine headache attacks and oxidative stress in otherwise healthy subjects with migraine and moderate headache (MH).

METHODS

To manage MH, these subjects used only a few drugs (antiemetics, analgesics on demand) and lifestyle changes; only very occasionally they used other, more specific products such as triptans. Study groups: one group used only standard management (SM), basically, management on demand. Oral magnesium and riboflavin (vitamin B2) were used with lipoic acid as they are considered useful to improve MH. Another group used the supplement Pycnogenol® (150 mg/day for 8 weeks) in addition to SM. These two groups were compared to a third (non-parallel, observational) group using topiramate (50 mg/day). If needed, subjects were allowed to use rescue medications.

RESULTS

Forty-six subjects were included in the study. Twenty-two used the standard management and 24 were supplemented with Pycnogenol® in association with SM. In addition, 21 subjects were treated with topiramate. Safety with Pycnogenol® was very good. The two main management groups and the third non-parallel group had comparable baseline characteristics. The number of migraine attacks were significantly reduced during the observation period with Pycnogenol® (P<0.05) in comparison with SM. Supplementation was more effective in reducing the use of rescue medications (P<0.05) including analgesics compared to SM. At 8 weeks, the pain score was lower with Pycnogenol in comparison with SM (P<0.05). The working incapacity was significantly lower with Pycnogenol® than in the SM group (P<0.05). The number of migraine attacks was lower with topiramate compared to SM. Pain score, working incapacity and use of rescue medication were lower with topiramate than in SM. However, adverse effects with topiramate, included paresthesia, fatigue, dizziness and nausea even at low dosages complicated management. Some 50% of these side effects require a form of further treatment including medications. Oxidative stress: all included subjects had high oxidative stress at baseline. At 8 weeks, the level of plasma free radicals was significantly lowered with Pycnogenol® (P<0.05), but not in the SM or topiramate group.

CONCLUSIONS

Pycnogenol® used as prophylaxis appears to reduce pain and the number and severity of symptoms in MH in parallel with a reduction of oxidative stress.

Preventive Treatment for Episodic Migraine

Episodic migraine is a debilitating condition. Preventive therapy is used to reduce frequency, duration, or severity of attacks. This review discusses principles of preventive treatment with a focus on preventive treatment options for people with episodic migraine. Specifically discussed is evidence and use of new migraine-specific treatment options for episodic migraine, such as calcitonin gene-related peptide monoclonal antibodies, a noninvasive transcutaneous electrical nerve stimulation device, and a single-pulse transcranial magnetic stimulator device. Also discussed are evidence-based updates from the 2012 American Academy of Neurology and the American Headache Society guidelines regarding major medication classes recommended for preventive episodic migraine treatment.

Current Status of Antiepileptic Drugs as Preventive Migraine Therapy

BACKGROUND

Antiepileptic drugs (AEDs) are an important class of agents used in the treatment of migraine, a neurological disorder that imparts significant socioeconomic burden. It is important for neurologists to understand the rationale for AEDs in migraine-preventive treatment, as well as each agent's efficacy and tolerability profile, in order to best determine clinical care.

PURPOSE OF THIS REVIEW

This article specifically provides the following: (1) a review of the mechanism of action, efficacy, and tolerability of topiramate and divalproex sodium/sodium valproate, the most widely used AEDs for migraine prevention, (2) a discussion on emerging evidence regarding the efficacy of zonisamide and levetiracetam, and (3) comments on gabapentin, pregabalin, carbamazepine, oxcarbazepine, and lamotrigine, AEDs which have insufficient evidence for use in migraine prevention.

RECENT FINDINGS

The potential role for new extended-release formulations of topiramate in migraine prevention is discussed. There is substantial evidence supporting the use of AEDs in migraine prevention. Specific agents should be chosen based on their efficacy and tolerability profiles. Further studies are needed to determine the efficacy of the newer AEDs, zonisamide and levetiracetam, in migraine prevention and to clarify the role of gabapentinoids in headache management.

Migraine Progression: A Systematic Review

BACKGROUND

Migraine is a common and often debilitating neurological disease. It can be divided into episodic and chronic subforms based on the number of monthly headache days. Because only a subset of individuals with episodic migraine (EM) progress to chronic migraine (CM) over any given time period, understanding the factors that predict the new onset of CM or "migraine progression" may provide insights into the mechanisms, pathophysiology, prevention, and treatment of CM. In this review, we identify and summarize studies that report risk factors associated with the new onset of CM or related chronic headache diagnoses, group these risk factors and report the strength of evidence for the identified risk factors.

OBJECTIVE

To conduct a systematic review of studies that identify risk factors for the new onset of CM or related chronic headache diagnoses such as transformed migraine (TM) and chronic daily headache (CDH).

METHODS

Herein we summarize the findings of studies of risk factors associated with the new onset of CM/TM, CDH, or related diagnoses from the English language literature published before March 2018. The PubMed database was searched for relevant studies. Longitudinal studies with follow-up data and case-control studies were included in this qualitative synthesis. We report methodology, analytic criteria, and results for each manuscript and for the parent study. Next, we review the strength of evidence for each of the identified risk factors using a modified version of AB Hill's criteria for causation and rank evidence as fair, moderate, or strong. We categorized risk factors as nonmodifiable, modifiable and based on putative mechanisms. We further categorized risk factors into sociodemographics, lifestyle factors and habits, headache features, comorbid and concomitant diseases and conditions and pharmacologic treatment-related. Finally, we review theories of the pathophysiology underlying the development of new onset chronic migraine or increasing attack frequency.

RESULTS

The PubMed search yielded 1870 records after duplicates were removed. Nine additional records were identified through expert consultation and other methods (eg, citations found as references in manuscripts identified in the literature review and through communication with the authors of manuscripts included in the review). The 1879 manuscripts were screened against the inclusion and exclusion criteria and 109 were found to be potentially eligible. Of 109 full-text articles, 17 studies were identified as meeting the prespecified criteria based on the consensus of all authors. Of the 17 full texts, 13 were longitudinal cohort studies and 4 were case-controlled studies. We found strength of evidence ranging from fair to strong for the identified risk factors. The strongest data were found for increased headache day frequency, depression, and medication overuse/high-frequency use. Risk factors for new onset CM and CDH in children and adolescents were similar to those identified in adults.

CONCLUSIONS

A range of risk factors for the new onset of CM/TM, CDH, or related chronic headache diseases were identified with the strongest data supporting increased headache day frequency, acute medication overuse/high-frequency use and depression, which are potentially modifiable risk factors. Modifiable risk factors may provide targets for intervention. The lack of strong evidence or any evidence does not imply that there is not a relationship between a particular risk factor and new onset CM or related disease; but may indicate little or no research or that research did not have sufficient methodological rigor. In addition, it is likely that additional risk factors exist which have not yet been identified. Putative factors include pro-inflammatory states and pro-thrombotic states. Development of central sensitization and increased activation of the trigeminal nociceptive pathways may be drivers of the new onset of CM or CDH. Future research may include the systematic testing of interventions targeting modifiable risk factors to determine if progression can be prevented as well as continued exploration of the benefits of treating these risk factors among people with CM in an effort to increase rates of remission. Future work should also consider the natural fluctuations in headache day frequency and examine progression in terms of continuous definitions rather than or in addition to a dichotomous boundary.

Evaluating the reporting of adverse events in controlled clinical trials conducted in 2010–2015 on migraine drug treatments

Background

In 2008, the International Headache Society published guidelines on the “evaluation and registration of adverse events in clinical drug trials on migraine”. They listed seven recommendations for reporting adverse events in randomized controlled trials on migraine. The present study aimed to evaluate adherence to these recommendations, and based on the results, to recommend improvements.

Methods

We searched the PubMed/MEDLINE database to identify controlled trials on migraine drugs published from 2010 to 2015. For each trial, we noted whether five of the recommended parameters were presented. In addition, we noted whether adverse events were reported in abstracts.

Results

We identified 73 trials; 51 studied acutely administered drugs and 22 studied prophylactic drugs for migraine. The number of patients with any adverse events were reported in 74% of acute-administration and 86% of prophylactic drug trials. Only 30 (41%) of the 73 studies reported adverse events with data in the abstracts, and 27 (37%) abstracts did not mention adverse events.

Conclusion

Adverse events, both frequency and symptoms, should be reported to allow a fair judgement of benefit/tolerability ratio when randomized controlled trials in migraine treatment are published. Clinically significant adverse events should be included in the abstract of every randomized controlled trial in migraine treatment.

Unveiling the relative efficacy, safety and tolerability of prophylactic medications for migraine: pairwise and network-meta analysis

BACKGROUND

A large number patients struggle with migraine which is classified as a chronic disorder. The relative efficacy, safety and tolerability of prophylactic medications for migraine play a key role in managing this disease.

METHODS

We conducted an extensive literature search for popular prophylactic medications that are used for migraine patients. Pairwise meta-analysis and network meta-analysis (NMA) were carried out sequentially for determining the relative efficacy, safety and tolerability of prophylactic medications. Summary effect for migraine headache days, headache frequency, at least 50% reduction in headache attacks, all-adverse events, nausea, somnolence, dizziness, withdrawal and withdrawal due to adverse events were produced by synthesizing both direct and indirect evidence.

RESULTS

Patients with three interventions exhibited significantly less average migraine headache days compared with those treated by placebo (topiramate, propranolol, divalproex). Moreover, topiramate and valproate exhibited a significantly increased likelihood of at least 50% reduction in migraine headache attacks compared to placebo. Patients with topiramate and propranolol also exhibited significantly reduced headache frequency compared to those with placebo. On the other hand, patients with divalproex exhibited significantly higher risk of nausea compared to those with placebo, topiramate, propranolol, gabapentin and amitriptyline. Finally, divalproex was associated with an increased risk of withdrawal compared to placebo and propranolol.

CONCLUSIONS

Topiramate, propranolol and divalproex may be more efficacious than other prophylactic medications. Besides, the safety and tolerability of divalproex should be further verified by future studies.

Minority Representation in Migraine Treatment Trials

BACKGROUND

Minorities have historically been underrepresented in clinical research trials despite having comparatively poor health indicators. Recognizing the dual inequalities of increased disease burden and decreased research participation, the National Institute of Health (NIH) Revitalization Act of 1993 mandated the inclusion and reporting of women and minorities in NIH-funded research. While progress has been made in the subsequent decades, this underrepresentation of minorities in research trials persists and has been documented in multiple disciplines. However, the extent of adequate representation and reporting of minority inclusion in clinical trials for migraine remains unknown.

OBJECTIVES

In this systematic review and study, we review the literature examining the representation of women and minorities in migraine clinical research trials METHODS: First we searched PubMed for pertinent articles examining the inclusion of women and minorities in migraine clinical research trials. Second, we identified controlled-trials for migraine published since 2011 in major neurology, headache, and general medicine journals using the terms "migraine randomized controlled trial." We then reviewed the results manually and excluded pilot studies and those with fewer than 50 participants. We next determined (a) how frequently representation of minorities and women were reported in these major trials; (b) what factors correlated with reporting; and (c) whether women and minority inclusion comprised their ratios in the general population.

RESULTS

We identified 128 relevant clinical trials, of which 36 met our inclusion criteria. All 36 trials (100%) reported gender frequency, and 25 of 36 (69.4%) reported ethnicity or race. Among all studies, women and Whites represented 84.2 and 82.9% of participants (mean), respectively. Studies conducted in the United States and funded by a private company were more likely to report race than studies conducted exclusively outside of the U.S. or with a public sponsor. No studies stratified efficacy or safety by ethnicity or gender. Men and non-Whites in the U.S. were statistically underrepresented.

CONCLUSIONS

Most recent headache studies comply with the NIH mandate to include women and minorities in research trials, particularly U.S.-based and industry-funded studies. Whites are overrepresented compared to both the general population and the population of migraineurs. Future studies should strive to increase minority participation and investigate race-based differences in migraine expression, treatment response, and medication toxicity.

Topiramate in Migraine Prevention: A 2016 Perspective

BACKGROUND

In evidence-based guidelines published in 2000, topiramate was a third-tier migraine preventive with no scientific evidence of efficacy; recommendation for its use reflected consensus opinion and clinical experience. Its neurostabilizing activity, coupled with its favorable weight profile, made topiramate an attractive alternative to other migraine preventives that caused weight gain. When guidelines for migraine prevention in episodic migraine were published in 2012, topiramate was included as a first-line option based on double-blind, randomized controlled trials involving nearly 3000 patients. The scientific and clinical interest in topiramate has generated a large body of data from randomized controlled trials, meta-analyses, patient registries, cohort studies, and claims data analyses that have more fully characterized its role as a migraine preventive.

AIM

This article will review the profile of topiramate that has emerged out of the past decade of research and clinical use in migraine prophylaxis. It will also address the rationale for extended-release (XR) formulations in optimizing topiramate therapy in migraine.

SUMMARY

Topiramate has activity at multiple molecular targets, which may account for why it is effective in migraine and most other, more specific, anticonvulsants are not. Based on randomized controlled trials, topiramate reduces migraine frequency and acute medication use, improves quality of life, and reduces disability in patients with episodic migraine and in those with chronic migraine with or without medication overuse headache. Its efficacy in chronic migraine is not improved by the addition of propranolol. Topiramate's ability to prevent progression from high-frequency episodic migraine to chronic migraine remains unclear. Consistent with clinicians' perceptions, migraineurs are more sensitive to topiramate-associated side effects than patients with epilepsy. Paresthesia is a common occurrence early in treatment but is rarely cause for terminating topiramate treatment. Cognitive problems occur much less frequently than paresthesia but are more troublesome in terms of treatment discontinuation. Cognitive complaints can often be managed by slowly increasing the topiramate dose in small increments to allow habituation. As with other carbonic anhydrase inhibitors, topiramate has metabolic effects that favor the development of metabolic acidosis and possibly renal stones. Because migraineurs have an increased risk of renal stones independent of topiramate exposure, clinicians should counsel all migraine patients to maintain hydration. Abrupt onset of blurring, other visual disturbances, and/or ocular pain following topiramate's initiation should be evaluated promptly since this may indicate rare but potentially sight-threatening idiosyncratic events. Postmarketing evidence has shown that first-trimester exposure to topiramate monotherapy is associated with increased occurrence of cleft lip with or without cleft palate (Pregnancy Category D). Even though topiramate's long half-life would seemingly support q.d. dosing, randomized controlled migraine trials used b.i.d. administration of immediate-release (IR) topiramate, which has more favorable plasma concentration-time profile (ie, lower peak concentrations and higher trough concentrations) than q.d. IR dosing. Given the sensitivity of migraineurs to topiramate-related adverse events, particularly cognitive effects, pharmacokinetic profiles should be considered when optimizing migraine outcomes. The extended-release (XR) formulations Qudexy^® XR (Upsher-Smith Laboratories) and Trokendi XR^® (Supernus Pharmaceuticals) were specifically designed to achieve the adherence benefits of q.d. dosing but with more favorable (ie, more constant) steady-state plasma concentrations over the 24-hour dosing interval vs IR topiramate b.i.d. Intriguing results from a study in healthy volunteers showed consistently less impairment in neuropsychometric tests of verbal fluency and mental processing speed with an XR topiramate formulation (Trokendi XR) vs IR topiramate b.i.d. These findings suggest a pharmacodynamic effect associated with significantly reducing plasma concentration fluctuation when topiramate absorption is slowed. Results of retrospective studies in migraineurs treated with XR topiramate appear to support a clinically meaningful benefit of XR topiramate vs IR topiramate in terms of significantly fewer cognitive effects, improved adherence, and overall better outcomes of migraine prophylaxis with topiramate.

Chronic migraine: risk factors, mechanisms and treatment

Chronic migraine has a great detrimental influence on a patient's life, with a severe impact on socioeconomic functioning and quality of life. Chronic migraine affects 1-2% of the general population, and about 8% of patients with migraine; it usually develops from episodic migraine at an annual conversion rate of about 3%. The chronification is reversible: about 26% of patients with chronic migraine go into remission within 2 years of chronification. The most important modifiable risk factors for chronic migraine include overuse of acute migraine medication, ineffective acute treatment, obesity, depression and stressful life events. Moreover, age, female sex and low educational status increase the risk of chronic migraine. The pathophysiology of migraine chronification can be understood as a threshold problem: certain predisposing factors, combined with frequent headache pain, lower the threshold of migraine attacks, thereby increasing the risk of chronic migraine. Treatment options include oral medications, nerve blockade with local anaesthetics or corticoids, and neuromodulation. Well-defined diagnostic criteria are crucial for the identification of chronic migraine. The International Headache Society classification of chronic migraine was recently updated, and now allows co-diagnosis of chronic migraine and medication overuse headache. This Review provides an up-to-date overview of the classification of chronic migraine, basic mechanisms and risk factors of migraine chronification, and the currently established treatment options.

New players in the preventive treatment of migraine

Migraine is a common, chronic disorder of the brain causing much disability, as well as personal, familial and societal impact. Several oral preventive agents are available in different countries for the prevention of migraine, but none have performed better than 50% improvement in 50% of patients in a clinical trial. Additionally, each has various possible adverse events making their tolerability less than optimal. Recently, three monoclonal antibodies targeting the calcitonin gene-related peptide (CGRP) ligand (LY2951742, ALD403 and TEV-48125) and one targeting the CGRP receptor (AMG 334) have completed phase 2 trials, and the results have been reported. These early results show them all to be somewhat more effective than placebo, with no serious adverse events. Three have been studied for episodic migraine, and only TEV-48125 has been studied for both high frequency episodic and chronic migraine. Moreover, preliminary data suggests that neurostimulation is effective in migraine treatment, including stimulation of the sphenopalatine ganglion, transcutaneous supraorbital and supratrochlear nerve, and transcutaneous vagus nerve. In this article, these innovative therapies will be reviewed.

A Comparative Effectiveness Meta-Analysis of Drugs for the Prophylaxis of Migraine Headache

OBJECTIVE

To compare the effectiveness and side effects of migraine prophylactic medications.

DESIGN

We performed a network meta-analysis. Data were extracted independently in duplicate and quality was assessed using both the JADAD and Cochrane Risk of Bias instruments. Data were pooled and network meta-analysis performed using random effects models.

DATA SOURCES

PUBMED, EMBASE, Cochrane Trial Registry, bibliography of retrieved articles through 18 May 2014.

ELIGIBILITY CRITERIA FOR SELECTING STUDIES

We included randomized controlled trials of adults with migraine headaches of at least 4 weeks in duration.

RESULTS

Placebo controlled trials included alpha blockers (n = 9), angiotensin converting enzyme inhibitors (n = 3), angiotensin receptor blockers (n = 3), anticonvulsants (n = 32), beta-blockers (n = 39), calcium channel blockers (n = 12), flunarizine (n = 7), serotonin reuptake inhibitors (n = 6), serotonin norepinephrine reuptake inhibitors (n = 1) serotonin agonists (n = 9) and tricyclic antidepressants (n = 11). In addition there were 53 trials comparing different drugs. Drugs with at least 3 trials that were more effective than placebo for episodic migraines included amitriptyline (SMD: -1.2, 95% CI: -1.7 to -0.82), -flunarizine (-1.1 headaches/month (ha/month), 95% CI: -1.6 to -0.67), fluoxetine (SMD: -0.57, 95% CI: -0.97 to -0.17), metoprolol (-0.94 ha/month, 95% CI: -1.4 to -0.46), pizotifen (-0.43 ha/month, 95% CI: -0.6 to -0.21), propranolol (-1.3 ha/month, 95% CI: -2.0 to -0.62), topiramate (-1.1 ha/month, 95% CI: -1.9 to -0.73) and valproate (-1.5 ha/month, 95% CI: -2.1 to -0.8). Several effective drugs with less than 3 trials included: 3 ace inhibitors (enalapril, lisinopril, captopril), two angiotensin receptor blockers (candesartan, telmisartan), two anticonvulsants (lamotrigine, levetiracetam), and several beta-blockers (atenolol, bisoprolol, timolol). Network meta-analysis found amitriptyline to be better than several other medications including candesartan, fluoxetine, propranolol, topiramate and valproate and no different than atenolol, flunarizine, clomipramine or metoprolol.

CONCLUSION

Several drugs good evidence supporting efficacy. There is weak evidence supporting amitriptyline's superiority over some drugs. Selection of prophylactic medication should be tailored according to patient preferences, characteristics and side effect profiles.

Adding Additional Acute Medications to a Triptan Regimen for Migraine and Observed Changes in Headache-Related Disability: Results From the American Migraine Prevalence and Prevention (AMPP) Study

BACKGROUND

Though triptans are the most widely used acute treatments for migraine, response to treatment is sometimes suboptimal. Triptan therapy is often augmented by the addition of other acute treatments. The benefits of this practice have not been examined in large-scale, real-world observational studies.

OBJECTIVES

To assess changes in headache-related disability associated with adding additional acute treatments to a triptan regimen by category of added treatment including: a second triptan, nonsteroidal anti-inflammatory drugs (NSAID), opioids or barbiturates.

METHODS

Subjects were participants in the American Migraine Prevalence and Prevention study, a longitudinal, US population-based study of individuals with "severe" headache. Respondents who met International Classification of Headache Disorders 3 beta criteria for migraine were on triptan therapy per respondent self-report, used the same triptan, and provided headache-related disability data for at least 2 consecutive years. Subjects were divided based on headache days per month into 3 groups: low-frequency episodic migraine (LFEM, 0-4), moderate-frequency episodic migraine (MFEM, 5-9), and high-frequency episodic migraine/chronic migraine (HFEM/CM, ≥ 10 headache days per month). HFEM and CM were combined into a single group for analyses because of sample size limitations. Patterns of acute treatment for migraine were monitored from one year to the next over the following couplets of years (2005-2006, 2006-2007, 2007-2008, and 2008-2009). The first eligible couplet was analyzed for each respondent. Medication regimens studied included: (1) maintaining current triptan use (consistent group); (2) adding a different triptan; (3) adding an NSAID; or (4) adding a combination analgesic containing opioids or barbiturates. We assessed change in Migraine Disability Assessment (MIDAS) score from the first to the second year of a couplet, contrasting scores of participants with consistent use with those who added an acute treatment to their triptan regimen.

RESULTS

The study sample (N = 2128) included 111 individuals who added another triptan, 118 who added an opioid or barbiturate, and 69 who added an NSAID, with referent groups of approximately 600 cases in each group who remained consistent. In general, MIDAS scores were higher among those who made changes from one year to the next compared with those who did not make changes in therapy. In fully adjusted models, adding triptans or NSAIDs was associated with increased disability for HFEM/CM cases at follow-up but decreased disability at follow-up for MFEM cases, resulting in significant interaction effects for both adding triptans and NSAIDs, respectively (15.88, 95% confidence interval [CI] 0.75, 31.01, 38.52, 95% CI 12.43, 64.61).

CONCLUSIONS

While the effects of adding vs staying consistent on the outcome of headache-related disability varied by medication type added and headache frequency strata, in general, these results suggest that for individuals with migraine, adding acute therapies to current triptan use is generally not associated with reductions in headache-related disability. The results were strongest among persons with HFEM and CM. These results identify important unmet medical needs in current migraine management, especially among patients with high-frequency migraine, and suggest that alternative treatment strategies are needed to improve patient outcomes.

Antiepileptics in migraine prophylaxis: an updated Cochrane review

INTRODUCTION

The efficacy of several antiepileptics in the preventive treatment of episodic migraine in adults has been systematically reviewed. Because many trial reports have been published since then, an updated systematic review was warranted.

METHODS

We searched the Cochrane Central Register of Controlled Trials, PubMed/MEDLINE (1966 to January 15, 2013), MEDLINE In-Process (current week, January 15, 2013), and EMBASE (1974 to January 15, 2013) and hand-searched Headache and Cephalalgia through January 2013. Prospective, controlled trials of antiepileptics taken regularly to prevent the occurrence of migraine attacks, to improve migraine-related quality of life, or both, were selected.

RESULTS

Mean headache frequency on topiramate and sodium valproate is significantly lower than placebo. Likewise, topiramate and divalproex demonstrated favorable results for the proportion of subjects with ≥ 50% reduction of migraine attacks. For topiramate, 100 mg and 200 mg outperformed 50 mg, but this was paralleled by a higher adverse event rate. For valproate/divalproex, a dose-effect correlation could not be established. There was no unequivocal evidence of efficacy for any of the other antiepileptics.

CONCLUSION

Topiramate, sodium valproate and divalproex are effective prophylactic treatments for episodic migraine in adults. In contrast to previous reports, there is insufficient evidence to further support the use of gabapentin.

Topiramate and cognitive impairment: evidence and clinical implications

Topiramate is an antiepileptic drug (AED) with multiple mechanisms of action that has been shown to be effective in a number of neuropsychiatric disorders. However, cognitive dysfunction is frequently observed in such patients, often representing a relevant challenge in their management. Moreover, there is a long-held recognition that AEDs may profoundly affect cognitive functions. This paper reviews available data on cognitive adverse events in patients with neurological disorders treated with topiramate, discussing the role of different contributing factors such as the pharmacological properties of the drug, the specific features of the brain disorder, and other variables pertinent to the discussion. All studies agree that up to 10% of patients may complain of treatment-emergent adverse events on cognition. Such problems occur early during treatment (i.e. within 6 weeks) and emerge in a dose-dependent fashion, suggesting that such prevalence may be significantly reduced using the drug in monotherapy and adopting individualized doses and titration schedules. The magnitude of the problem is generally mild to moderate and the subjective perception of the patient needs to be taken into account. In fact, apart from language problems, data are not conclusive. Comparisons with new AEDs are limited to levetiracetam and lamotrigine, in both cases generally disfavoring topiramate, while data regarding first-generation AEDs show clear differences only for verbal fluency.

SumaRT/Nap vs naproxen sodium in treatment and disease modification of migraine: a pilot study

OBJECTIVE

This pilot study explored the potential for 2 recognized acute migraine medications, 85 mg of sumatriptan plus 500 mg of naproxen sodium in a combination tablet (SumaRT/Nap) and 500 mg of naproxen sodium, to treat and modify the disease progression of migraine. In other words, can these medications both abort an acute attack of migraine and reduce the number of future migraine attacks?

BACKGROUND

Patients suffering with moderate to severe attacks of migraine desire acute treatment. As migraine frequency increases, so does the need for more frequent relief of acute attacks. This may lead to medication overuse and potentially medication overuse headache (MOH). Ideally, acute medication would have the ability to abort an attack of migraine and reduce the likelihood of future attacks.

STUDY DESIGN

The primary endpoint of this study was a reduction in migraine headache days from baseline through month 3 of the study. Subjects were randomized 1:1 to treat 14 or fewer migraines per month with SumaRT/Nap (Group A) or naproxen sodium (Group B) for 3 months. Subjects in group A utilized SumaRT/Nap were encouraged, but not required, to treat migraine headache within 1 hour of onset of headache when the pain was mild. They could re-treat if needed after 2 hours. Subjects in group B utilized the same treatment strategy with 500 mg of naproxen sodium. Tablets of study medication were identical for both groups. Subjects recorded headache days, migraine attacks, duration of attacks, treatment, and treatment results daily on paper diaries. Subjects took the Migraine Disability Assessment Test (MIDAS) at randomization and 3 months later at the end of study.

RESULTS

Naproxen sodium was associated with a statistically significant reduction in migraine headache days at month 3 compared to baseline (P = .0002). SumaRT/Nap was also associated with a reduction of migraine headache days, but this decrease did not reach statistical significance (P = .2). In addition, subjects in the naproxen sodium group had a statistically significant reduction of migraine attacks in all 3 months of the study compared to baseline. A greater than 50% reduction in the number of migraine headache days at month 3 occurred in 43% (6/14) of subjects in group B compared to 17% (3/18) of subjects in group A. Consistent with large regulatory studies comparing the efficacy of SumaRT/Nap with naproxen sodium, SumaRT/Nap in this study was statistically superior to naproxen sodium at 2 hours in reducing headache severity during months 2 and 3. There was a reduction of acute medication used from baseline to month 3 and improvement in MIDAS scores for both groups.

CONCLUSION

Naproxen sodium, when used as a sole acute treatment early in attacks, appears to reduce the frequency of headache days and migraine attacks for a select number of subjects over a 3-month period. SumaRT/Nap is more effective at 2-hour headache reduction than naproxen sodium alone, but has less impact on reducing attack frequency or the number of headache days. Both treatments were well tolerated, and there was no convincing evidence that either medication led to MOH.

Preventive pharmacologic treatments for episodic migraine in adults

OBJECTIVES

Systematic review of preventive pharmacologic treatments for community-dwelling adults with episodic migraine.

DATA SOURCES

Electronic databases through May 20, 2012.

ELIGIBILITY CRITERIA

English-language randomized controlled trials (RCTs) of preventive drugs compared to placebo or active treatments examining rates of ≥50 % reduction in monthly migraine frequency or improvement in quality of life.

STUDY APPRAISAL AND SYNTHESIS METHODS

We assessed risk of bias and strength of evidence and conducted random effects meta-analyses of absolute risk differences and Bayesian network meta-analysis.

RESULTS

Of 5,244 retrieved references, 215 publications of RCTs provided mostly low-strength evidence because of the risk of bias and imprecision. RCTs examined 59 drugs from 14 drug classes. All approved drugs, including topiramate (9 RCTs), divalproex (3 RCTs), timolol (3 RCTs), and propranolol (4 RCTs); off-label beta blockers metoprolol (4 RCTs), atenolol (1 RCT), nadolol (1 RCT), and acebutolol (1 RCT); angiotensin-converting enzyme inhibitors captopril (1 RCT) and lisinopril (1 RCT); and angiotensin II receptor blocker candesartan (1 RCT), outperformed placebo in reducing monthly migraine frequency by ≥50 % in 200-400 patients per 1,000 treated. Adverse effects leading to treatment discontinuation (68 RCTs) were greater with topiramate, off-label antiepileptics, and antidepressants than with placebo. Limited direct evidence as well as frequentist and exploratory network Bayesian meta-analysis showed no statistically significant differences in benefits between approved drugs. Off-label angiotensin-inhibiting drugs and beta-blockers were most effective and tolerable for episodic migraine prevention.

LIMITATIONS

We did not quantify reporting bias or contact principal investigators regarding unpublished trials.

CONCLUSIONS

Approved drugs prevented episodic migraine frequency by ≥50 % with no statistically significant difference between them. Exploratory network meta-analysis suggested that off-label angiotensin-inhibiting drugs and beta-blockers had favorable benefit-to-harm ratios. Evidence is lacking for long-term effects of drug treatments (i.e., trials of more than 3 months duration), especially for quality of life.

Effects of switching acute treatment on disability in migraine patients using triptans

OBJECTIVE

To assess the influence of switching acute treatment on headache-related disability in a population sample of individuals with migraine using acute triptan therapy.

BACKGROUND

Acute treatments for migraine are often modified in clinical practice. The effect of changes in treatment from one triptan to another or from a triptan to another medication class has rarely been studied.

METHODS

Patterns of acute treatment for migraine were monitored from 1 year to the next in the American Migraine Prevalence and Prevention (AMPP) Study for the following couplets (2005-2006, 2006-2007, 2007-2008, and 2008-2009). Changes in medication regimens were classified as follows: (1) switch within the triptan class; (2) switch to combination analgesics containing opioids or barbiturates; (3) switch to non-steroidal anti-inflammatory drug (NSAID) agents; (4) maintaining current therapy (consistent use, "control"). We assessed change in migraine disability assessment scale score from the first to the second year of a couplet contrasting those with consistent use with those who changed acute treatment. Each individual contributed only 1 couplet to the analysis. Persons who added an acute treatment are considered in a separate manuscript. We modeled change in migraine disability assessment scale score as a function of change in medication regimen with consistent users as the control group.

RESULTS

We identified 81 individuals who switched to another triptan, with a referent of 619 who remained consistent, 31 cases who switched to an opioid or barbiturate with a referent of 666 who remained consistent, and 20 cases who switched to an NSAID with a referent of 667 cases who remained consistent. In cell-mean coded analyses of covariance (ANCOVA), switching from one triptan to another or switching from a triptan to an opioid/barbiturate was never associated with significant improvements in headache-related disability compared with consistent treatment. Switching from a triptan to an NSAID was associated with significant increases in headache-related disability among those with high-frequency episodic/chronic migraine (HFEM/CM) compared with those with low-frequency episodic migraine (LFEM) (interaction = 34.81, 95% confidence interval 10.61 to 59.00). The same was true comparing high-frequency episodic/chronic migraine with those with moderate-frequency episodic migraine (interaction = 48.73, 95% confidence interval 2.63 to 94.83).

CONCLUSIONS

In this observational study, switching triptan regimens does not appear to be associated with improvements in headache-related disability and in some cases is associated with increased headache-related disability.

Topiramate for the prophylaxis of episodic migraine in adults

BACKGROUND

Some antiepileptic drugs but not others are useful in clinical practice for the prophylaxis of migraine. This might be explained by the variety of actions of these drugs in the central nervous system. The present review is part of an update of a Cochrane review first published in 2004, and previously updated (conclusions not changed) in 2007.

OBJECTIVES

To describe and assess the evidence from controlled trials on the efficacy and tolerability of topiramate for preventing migraine attacks in adult patients with episodic migraine.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL; The Cochrane Library 2012, Issue 12), PubMed/MEDLINE (1966 to 15 January 2013), MEDLINE In-Process (current week, 15 January 2013), and EMBASE (1974 to 15 January 2013) and handsearched Headache and Cephalalgia through January 2013.

SELECTION CRITERIA

Studies were required to be prospective, controlled trials of topiramate taken regularly to prevent the occurrence of migraine attacks, to improve migraine-related quality of life, or both.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected studies and extracted data. For headache frequency data, we calculated mean differences (MDs) between topiramate and comparator (placebo, active control, or topiramate in a different dose) for individual studies and pooled these across studies. For dichotomous data on responders (patients with ≥ 50% reduction in headache frequency), we calculated odds ratios (ORs) and, in select cases, risk ratios (RRs); we also calculated numbers needed to treat (NNTs). We calculated MDs for selected quality of life instruments. Finally, we summarised data on adverse events from placebo-controlled trials and calculated risk differences (RDs) and numbers needed to harm (NNHs).

MAIN RESULTS

Twenty papers describing 17 unique trials met the inclusion criteria. Analysis of data from nine trials (1737 participants) showed that topiramate reduced headache frequency by about 1.2 attacks per 28 days as compared to placebo (MD -1.20; 95% confidence interval (CI) -1.59 to -0.80). Data from nine trials (1190 participants) show that topiramate approximately doubled the proportion of responders relative to placebo (RR 2.02; 95% CI 1.57 to 2.60; NNT 4; 95% CI 3 to 6). Separate analysis of different topiramate doses produced similar MDs versus placebo at 50 mg (-0.95; 95% CI -1.95 to 0.04; three studies; 520 participants), 100 mg (-1.15; 95% CI -1.58 to -0.71; six studies; 1620 participants), and 200 mg (-0.94; 95% CI -1.53 to -0.36; five studies; 804 participants). All three doses significantly increased the proportion of responders relative to placebo; ORs were as follows: for 50 mg, 2.35 (95% CI 1.60 to 3.44; three studies; 519 participants); for 100 mg, 3.49 (95% CI 2.23 to 5.45; five studies; 852 participants); and for 200 mg, 2.49 (95% CI 1.61 to 3.87; six studies; 1025 participants). All three doses also significantly improved three or more domains of quality of life as compared to placebo. Meta-analysis of the three studies that included more than one dose of topiramate suggests that 200 mg is no more effective than 100 mg. With regard to mean headache frequency and/or responder rate, seven trials using active comparators found (a) no significant difference between topiramate and amitriptyline (one study, 330 participants); (b) no significant difference between topiramate and flunarizine (one study, 83 participants); (c) no significant difference between topiramate and propranolol (two studies, 342 participants); (d) no significant difference between topiramate and relaxation (one study, 61 participants); but (e) a slight significant advantage of topiramate over valproate (two studies, 120 participants). Relaxation improved migraine-specific quality of life significantly more than topiramate. In trials of topiramate against placebo, seven adverse events (AEs) were reported by at least three studies. These were usually mild and of a non-serious nature. Except for taste disturbance and weight loss, there were no significant differences in the frequency of AEs in general, or of the seven specific AEs, between placebo and topiramate 50 mg. AEs in general and all of the specific AEs except nausea were significantly more common on topiramate 100 mg than on placebo, with NNHs varying from 3 to 25, and the RDs versus placebo were even higher for topiramate 200 mg, with NNHs varying from 2 to 17.

AUTHORS' CONCLUSIONS

Meta-analysis demonstrates that topiramate in a 100 mg/day dosage is effective in reducing headache frequency and reasonably well-tolerated in adult patients with episodic migraine. This provides good evidence to support its use in routine clinical management. More studies designed specifically to compare the efficacy or safety of topiramate versus other interventions with proven efficacy in the prophylaxis of migraine are needed.

Topiramate in the treatment of migraine: A kainate (glutamate) receptor antagonist within the trigeminothalamic pathway

Background: The development of new agents for the preventive treatment of migraine is the greatest unmet need in the therapeutics of primary headaches. Topiramate, an anticonvulsant drug, is an effective anti-migraine preventive whose mechanism of action is not fully elucidated. Since glutamate plays a major role in migraine pathophysiology, the potential action of topiramate through glutamatergic mechanisms is of considerable interest.

Methods: Recordings of neurons in the trigeminocervical complex (TCC) and the ventroposteromedial thalamic nucleus (VPM) of anesthetized rats were made using electrophysiological techniques. The effects of intravenous or microiontophorezed topiramate on trigeminovascular activation of second- and third-order neurons in the trigeminothalamic pathway were characterized. The potential interactions of topiramate with the ionotropic glutamate receptors were studied using microiontophoresis.

Results: Both intravenous and microiontophorized topiramate significantly inhibited trigeminovascular activity in the TCC and VPM. In both nuclei microiontophoretic application of topiramate significantly attenuated kainate receptor-evoked firing but had no effect on N-methyl-d-aspartic acid or α-amino-3-hydroxyl-5-methyl-4-isoxazole-propionate receptor activation.

Conclusion: The data demonstrate for the first time that topiramate modulates trigeminovascular transmission within the trigeminothalamic pathway with the kainate receptor being a potential target. Understanding the mechanism of action of topiramate may help in the design of new medications for migraine prevention, with the data pointing to glutamate-kainate receptors as a fruitful target to pursue.

Treatment of migraine: update on new therapies

PURPOSE OF REVIEW

This review provides a comprehensive selection of the latest clinical trial results in antimigraine treatment.

RECENT FINDINGS

The oral calcitonine gene-related peptide antagonist telcagepant is efficacious in acute treatment. Compared to triptans, its efficacy is almost comparable but its tolerance is superior. The same is true for the 5HT-1F agonist lasmiditan, another agent devoid of vascular effects. Triptans, as other drugs, are more efficient if taken early but nonsteroidal anti-inflammatory drugs and analgesics remain useful for acute treatment, according to several meta-analyses. Single-pulse transcranial magnetic stimulation during the aura rendered more patients pain-free (39%) than sham stimulation (22%) in one study. Topiramate could be effective for migrainous vertigo, but it did not prevent transformation to chronic migraine in patients with high attack frequency. Onabotulinumtoxin A was effective for chronic migraine and well tolerated, but the therapeutic gain over placebo was modest; the clinical profile of responders remains to be determined before widespread use. Occipital nerve stimulation was effective in intractable chronic migraine with 39% of responders compared to 6% after sham stimulation. This and other neuromodulation techniques, such as sphenopalatine ganglion stimulation, are promising treatments for medically refractory patients but large controlled trials are necessary. One study suggests that outcome of patent foramen ovale closure in migraine might depend on anatomic and functional characteristics.

SUMMARY

Drugs with a better efficacy or side-effect profile than triptans may soon become available for acute treatment. The future may also look brighter for some of the very disabled chronic migraineurs thanks to novel drug and neuromodulation therapies.

Clinical pharmacology of topiramate in migraine prevention

INTRODUCTION

Migraine is a widespread disorder. Migraine patients experience worse health-related quality of life than the general population. The availability of effective and tolerable treatments for this disorder is an important medical need. This narrative review focuses on the clinical pharmacology of topiramate, an antiepileptic drug that was approved for the prophylaxis of migraine where it should act as a neuromodulator.

AREAS COVERED

A PubMed database search (from 2000 to 24 January 2011) and a review of the human studies published on topiramate and migraine was conducted.

EXPERT OPINION

Topiramate is an important option for the prophylaxis of migraine and is of proven efficacy and tolerability. It has also been studied in chronic migraine with encouraging results, even in patients with medication overuse. However, in migraine prevention its efficacy is comparable to the other first-line drugs and there are no published trials with a superiority design which can establish topiramate's role in the available therapeutic armamentarium.